反应详情

Add isopropyl chloroformate (19.8 mL, 19.8 mmol, 1.0 M in toluene) dropwise to a solution of 2-Amino-6-methyl-benzoic acid methyl ester (3.27 g, 19.8 mmol) and pyridine (4.0 mL, 50 mmol) in dichloromethane (39 mL) at 0° C. under an atmosphere of nitrogen and stir at room temperature for 14 h. Add 1M HCl and separate the layers. Extract the aqueous layer with dichloromethane. Dry the organic layer over anhydrous sodium sulfate, filter, and remove the solvent under reduced pressure. Purify the residue by flash chromatography, eluting with hexanes/ethyl acetate, to afford the title compound (3.80 g, 76%): 1H NMR (CDCl3) δ 1.29 (d, J=6.5 Hz, 6H), 2.43 (s, 3H), 3.94 (s, 3H), 5.00 (septuplet, J=6.5 Hz, 1H), 6.90 (d, J=8.1 Hz, 1H), 7.32 (t, J=8.1 Hz, 1H), 8.07 (d, J=8.1 Hz, 1H), 8.86 (brs, 1H). MS (ES+): 252 (M+H).

1. customseparate the layers
2. extractionExtract the aqueous layer with dichloromethane
3. dry with materialDry the organic layer over anhydrous sodium sulfate
4. filtrationfilter
5. customremove the solvent under reduced pressure
6. customPurify the residue by flash chromatography
7. washeluting with hexanes/ethyl acetate